The present invention relates to fluid supply nozzles, and more particularly relates to a fluid supply nozzle for use in substrate processing for a semiconductor device or a flat display panel (such as a liquid crystal display device and a plasma display panel (PDP)) and the like and substrate processing apparatus and method using the fluid supply nozzle.
As for processing of a semiconductor substrate using a fluid in process steps for fabricating a semiconductor device, not only wet etching of a semiconductor substrate but also cleaning of a semiconductor substrate using various types of fluids and the like are used. Such processing is performed in all places in process steps for fabricating a semiconductor device. Conventionally, a batch processing method in which a plurality of wafers are soaked in a fluid bath at a same time and then wet etching or cleaning is performed has been used in many cases. However, in such a batch processing method, whether the number of semiconductor substrates to be processed is large or small, a large fluid processing bath is needed. Therefore, with increase in the diameter of semiconductor substrates, the size of an entire fabrication apparatuses is increased.
Moreover, even though a plurality of semiconductor substrates are processed at a time using a batch processing apparatus, with the subsequent process step using a single-wafer-processing apparatus, a waiting time is different for each semiconductor substrate. As a result, in a semiconductor substrate which is to be left with a long waiting time after wet etching, an inconvenient phenomenon such as the generation of a natural oxide film on a surface of the semiconductor substrate, which affects device properties of a semiconductor device occurs.
Then, it has been proposed to use, as in other process steps, a single-wafer-processing apparatus for processing a semiconductor substrate one by one in a substrate processing apparatus using a fluid.
A single-wafer-processing substrate processing apparatus using a fluid supplies a fluid for a certain amount of time to a front or back surface of a semiconductor substrate from a fluid supply nozzle provided in the vicinity of a center portion of a semiconductor substrate and then performs wet etching or surface processing and the like, while rotating the semiconductor substrate placed on a rotation table. However, for a single-wafer-processing substrate processing apparatus using a fluid, the following problem arises with the increase in the diameter of semiconductor substrates.
That is, in the center portion of the semiconductor substrate, a large volume of a clean fluid is supplied and a surface of the semiconductor substrate is sufficiently processed with the fluid. However, in contrast, the volume of a processing fluid per unit area decreases in a closer portion of the semiconductor substrate to the periphery of the semiconductor substrate. Furthermore, the fluid is more deteriorated in a closer portion of the semiconductor substrate to the periphery of the semiconductor substrate, compared to the state of the fluid right after the fluid is discharged. Thus, it is difficult to uniformly perform processing in the semiconductor substrate.
A single-wafer-processing substrate processing apparatus for solving this problem has been proposed in Japanese Laid-Open Publication No. 2002-151455. Hereinafter, the single-wafer-processing substrate processing apparatus will be described with reference to the accompanying drawings.
FIG. 13 is a view schematically illustrating the structure of a known single-wafer-processing substrate processing apparatus using a fluid.
A rotation table 11 is provided in a processing chamber 10. The rotation table 11 is connected to a driving section 12 so as to be rotated due to a rotation operation of the driving section 12.
A silicon substrate 13 is provided on the rotation table 11 and is rotated with the rotation table 11.
A fluid supply nozzle 14 provided in an upper portion of the processing chamber 10 supplies a fluid 15 onto a silicon substrate 13, and the angle, direction and the like of the fluid supply nozzle 14 are controlled by a nozzle adjustment mechanism 16. In this case, the fluid 15 is a liquid such as a chemical solution, pure water and the like.
Moreover, the fluid 15 is supplied to the fluid supply nozzle 14 by a pump system 17, and the pump system 17 and the nozzle adjustment mechanism 16 are controlled by a control system 18. Thus, the flow rate or the like of the fluid 15 supplied onto the silicon substrate 13 is controlled according to processing so as to be an optimum level.
The fluid 15 used in processing of the silicon substrate 13 is discharged from the processing chamber 10 through a waste fluid discharge drain 19.
Such processing by the above-described processing apparatus is performed, with the silicon substrate 13 provided on the rotation table 11, by supplying the fluid 15 onto the silicon substrate 13 by the fluid supply nozzle 14 while rotating the silicon substrate 13.
The substrate processing apparatus of FIG. 13 uses the arrangement of fluid supply nozzles 14 for making processing in a plane of the silicon substrate 13 uniform. FIG. 14 is a plan view illustrating an example of the arrangement.
As shown in FIG. 14, assume that a position A is located in the vicinity of the center of the silicon substrate 13, a position B is located in a closer portion of the silicon substrate 13 to the periphery thereof than the position A, and a position C is located in a closer portion of the substrate 13 to the periphery thereof than the point B. In this case, a fluid supply nozzle 14a for supplying the fluid 15 to the position A, two fluid supply nozzles 14b for supplying the fluid 15 to the position B, four fluid supply nozzles 14c for supplying the fluid 15 to the position C are provided. That is, seven fluid supply nozzles 14 are used for total and are arranged so that more fluid supply nozzles are provided in a closer portion of the semiconductor substrate 13 to the periphery.
Thus, the flow rate of the fluid 15 in a peripheral portion of the silicon substrate 13 can be increased, so that the fluid can be uniformly supplied to the entire silicon substrate 13.
In addition to the above-described points, the nozzle adjustment mechanism 14 and the pump system 17 are controlled by the control system 18, so that a direction and an angle in which the fluid supply nozzle 14 discharges the fluid 15 and the flow rate of the fluid 15 and the like are set so as to be optimized according to processing to be performed to the silicon substrate 13.
Thus, when the silicon substrate 13 provided on the rotation table 11 is rotated and the fluid 15 is supplied from the seven fluid supply nozzles 14, the fluid 15 which is not deteriorated can be supplied over an entire surface of the silicon substrate 13. As a result, non-uniformness of processing performed to the silicon substrate 13 in a plane can be reduced.
Note that as a fluid supply nozzle in the known substrate processing apparatus, in general, a simple pipe is used.
Moreover, another example of processing apparatuses for performing uniform processing of an entire substrate is, for example, an apparatus disclosed in Japanese Laid-Open Publication No. 2001-68449.
According to the Japanese Laid-Open Publication No. 2001-68449, a plurality of fluid supply nozzles and a plurality of fluid recovery nozzles are arranged so that the entire surface of the silicon substrate 13 can be covered.